Imprints of Himalayan thrust tectonics on the Quaternary piedmont sediments of the Neora–Jaldhaka Valley, Darjeeling–Sikkim Sub-Himalayas, India

Guha, D. B.; Bardhan, Sandeep; Basir, Shaikh Rezaul; De, Adhip Kanti; Sarkar, Ashutosh

doi:10.1016/j.jseaes.2006.11.010

Cited by 42 publications

(22 citation statements)

References 7 publications

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“…The collision of the Indian and the Eurasian plates resulted in north-south contraction of the lithosphere and development of southward propagating fold and thrust belt (FTB) (Molnar and Tapponnier, 1975;Molnar, 1984;Guha et al, 2007). Himalayas are one of the few longest mountain ranges in the world, comparable with Andes, Rocky Mountains, Great Dividing Range etc.…”

Section: Introductionmentioning

confidence: 99%

“…It is a commonly accepted hypothesis that either the thrust tip is blind in most of the areas or its trace is buried by rapid accumulation of sediments (Raiverman et al, 1990;Valdiya et al, 1992;Srivastava and John, 1999;Mukul 2000;Sarkar and Som, 2001;Mukhopadhyay and Mishra, 2004). In the Darjeeling foothill Himalayas, to the east of the Tista River, the MFT has discontinuous and nonlinear surface expressions (Nakata, 1989;Guha et al, 2007;Goswami et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Thus, this fan provides an opportunity to explore climate-tectonics interactions. Guha et al (2007), based on their two radiocarbon dates, one near the Gorubathan thrust and another near the Chalsa thrust attempted to explain the evolution of fan. However, the C-14 age of 33,875 ± 550 Ybp near the Gorubathan thrust (Guha et al, 2007) gives only a lower bound and shows that the fan formation started before that.…”

Section: Introductionmentioning

confidence: 99%

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Luminescence chronology of alluvial fan in North Bengal, India: Implications to tectonics and climate

et al. 2016

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Alluvial fans are important geomorphic archives because of its strategic location at mountain front which can provide clues to the past climate and tectonics. In general, they provide information about optimum climate condition suitable for fan formation. We provide a detailed luminescence chronology of alluvial fan in north West Bengal, India. The regional fan surface (T44) has been dissected by E-W trending Himalayan thrusts known as Matiali and Chalsa thrusts and have various terraces named as T3, T2and youngest one as T1. Luminescence ages suggest that the formation of the alluvial fan (regional surface) started before 171 ka and continued till 72 ka covering a time span of nearly 100 ky; suggesting of weaker monsoon at 72 ka. Matiali fault activated after 171 ky. Chalsa fault is suggested to be active during 48–41 ka. The last aggradational phase was around 6 ka which led to the formation of T1aterrace. The study suggests that climatic fluctuation during the period were shaping the morphology of the alluvial fan, along with tectonic activities on the two faults.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Luminescence chronology of alluvial fan in North Bengal, India: Implications to tectonics and climate

et al. 2016

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“…It was, however, noted that many of the rivers follow tectonic lineaments and the River Chel under focus in this paper is one of them (Dasgupta et al, 2000). Nevertheless, several significant works on many of these rivers emerging from the Eastern Himalaya have been carried out on the foothills (Basu and Sarkar, 1990;Chakraborty and Ghosh, 2010;Chakraborty et al, 2013;Chakraborty and Mukhopadhyay, 2014;Fergusson, 1863;Guha et al, 2007;Morgan and Mc Intire, 1959). Neotectonic effect on these rivers on the fans is seldom addressed (Chakraborty and Ghosh, 2010 and references therein), although Mukherjee and Sarkar (1981) noted five morphotectonic units within the fan system of the River Tista, in the close vicinity of the River Chel.…”

Section: Geological Backgroundmentioning

confidence: 99%

“…In the study area in eastern India, the Tista and Neora fans received some attention, although neotectonic features intrinsic within the fans are seldom addressed (Chakraborty and Ghosh, 2010;Ghosh et al, 2005;Guha et al, 2007;Meetei et al, 2007). These authors considered the fans they studied as single units, although remote sensing study of Mukherjee and Sarkar (1981) recorded five different morphogenetic units in association with the River Tista.…”

Section: The Alluvial Fanmentioning

confidence: 99%

Overprint of neotectonism along the course of River Chel, North Bengal, India

Mandal

Sarkar

2016

Journal of Palaeogeography

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This paper aims to unveil neotectonic imprints in topography, drainage and sediments in the 46.25 km long course of the River Chel from its source down to its alluvial fan at the base of the Himalayan Mountain Front in the DarjeelingeJalpaiguri districts of India. A semi-circular ridge delimits its primary catchment. Within confinement of this watershed basin the drainage pattern is composite being convergent along the periphery and divergent on a butte inside. All these geomorphic neotectonic imprints are accompanied by ramp and flat structures and spectacular mylonitization of rocks.High hypsometric index and convex shape of the hypsometric curve derived from the central near-straight course of the river between the primary catchment and the Main Frontal Thrust (MFT) also reflects tectonic youthfulness of the river course. It is well manifested also in widely variable stream index and stream gradient index ratios (SL/K) often exceeding 2. In response to neotectonism, this river course as a whole shifted westward between 1962 and 2007. Maximum reduction of the stream gradient on top of the MFT is eloquent enough about recent uplift of the thrust ridge. The high average slope gradient of canyon wall about 45.68 is well consistent with this uplift. Very low channel-width/valley-height ratio along the river further corroborates the uplift. The alluvial fan system of the River Chel is comprised of five morphogenetic fans stacked one above another with a tendency to shrink and shift progressively upslope. They differ from each other in terms of tilt, axial orientation, primary depositional surface gradient and convexity in transverse section and thus present a writ of ongoing tectonism. Progressive upward increase in the share of distal crystalline rocks in clast composition within alluvial fan package is a clear proxy for southerly advancement of the MFT. Concomitant increase in maximum clast size is in good agreement with sediment source uplift. All the five fans are, however, dormant now. Present-day River Chel deeply incises through all of them and suggests further basement uplift in the context of frequent evidences of neotectonism all around, although the role of climate remains uncertain in absence of adequate data.

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Active Tectonics of Himalayan Frontal Fault Zone in the Sub-Himalaya

2020

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The Himalaya grew progressively with the development of fold-thrust systems towards foreland from north to south. The Cenozoic foreland basin of the Sub-Himalaya zone was developed in front of the rising Himalaya. It is bounded between the Main Boundary Thrust (MBT) and the Himalayan Frontal Thrust (HFT). The Himalayan Frontal Fault zone encompasses the frontal anticlines, dun (intermontane basins) and hinterland fold-thrusts. The tectonic geomorphological mapping and optical simulation luminescence (OSL) dating of geomorphic surfaces/sediments indicate Late Pleistocene-Holocene deformation in the foldthrust system of the Himalayan Frontal Fault zone. The frontal anticlines are developed as fault-bend folds over the HFT. The backlimbs of the anticlines are largely characterised with formation of intermontane basins of duns. The surface ruptures of past earthquakes are recorded in paleoseismological-investigated trenches over the Himalayan front along the HFT trace, whereas epicentres of the earthquakes are in the Lesser Himalayan hinterland. The HFT represents the surface expression of the Main Himalayan Thrust (MHT). The slip generated over the earthquake rupture is transferred to the MHT-HFT. This suggests coseismic slip contributes incrementally to the growth of the frontal anticlines. Using strath surfaces over the hanging walls of reverse faults, the uplift and shortening rates are computed. The estimated shortening rates are 18-20 mm/year in the central Himalaya and 13-15 mm/year in northwest Himalaya during Late Pleistocene-Holocene. The long-term shortening rates are nearly consistent with the current rates derived through geodetic (GPS) method. In the Sub-Himalayan hinterland, there are out-of-sequence faults which show Late Pleistocene-Holocene activation. Late Pleistocene activation is observed along certain segments of the MBT. Normal faulting is ascribed largely to activation of the MBT, whereas left-lateral sense of motion along fault scarp in the alluvial fan covering the MBT is also observed.

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Imprints of Himalayan thrust tectonics on the Quaternary piedmont sediments of the Neora–Jaldhaka Valley, Darjeeling–Sikkim Sub-Himalayas, India

Cited by 42 publications

References 7 publications

Luminescence chronology of alluvial fan in North Bengal, India: Implications to tectonics and climate

Luminescence chronology of alluvial fan in North Bengal, India: Implications to tectonics and climate

Overprint of neotectonism along the course of River Chel, North Bengal, India

Active Tectonics of Himalayan Frontal Fault Zone in the Sub-Himalaya

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